The efficacy of pocket eliminationreduction compared

Prévia do material em texto

J Clin Periodontol. 2020;47:303–319. wileyonlinelibrary.com/journal/jcpe  |  303© 2020 John Wiley & Sons A/S. 
Published by John Wiley & Sons Ltd
1  | INTRODUC TION
Periodontitis is a chronic inflammatory disease that leads to the 
destruction of the periodontal attachment apparatus and pos-
sible tooth loss (Page & Schroeder, 1976; Savage, Eaton, Moles, & 
Needleman, 2009). Disease progression induces an apical migration 
of the attachment apparatus with periodontal pocket formation 
(Bosshardt & Schroeder, 1988). The main goal of periodontal therapy 
is to arrest the destructive outcome of this disease. It is broadly ac-
cepted that probing pocket depth (PPD) reduction via various treat-
ment approaches may improve the prognosis of the individual teeth 
(Nunn et al., 2012). In order to maintain periodontal health, treat-
ment aims are to reduce PPD, maintain or improve clinical attach-
ment level (CAL), and resolve periodontal inflammation.
In view of the previous objectives, treatment of periodontitis in-
cludes a wide range of interventions: education of the patient for 
self-plaque control (Jonsson, Baker, Lindberg, Oscarson, & Ohrn, 
2012; Jonsson, Ohrn, Lindberg, & Oscarson, 2010), smoking ces-
sation (Chaffee, Couch, & Ryder, 2016; Ramseier & Suvan, 2015), 
 
Received: 14 August 2019  |  Revised: 17 December 2019  |  Accepted: 17 December 2019
DOI: 10.1111/jcpe.13246 
S Y S T E M A T I C R E V I E W
The efficacy of pocket elimination/reduction compared to 
access flap surgery: A systematic review and meta-analysis
David Polak1  | Asaf Wilensky1 | Georgios N. Antonoglou2  | Lior Shapira1  | 
Moshe Goldstein1 | Conchita Martin3
Polak and Wilensky contributed equally to the article. 
1Faculty of Dental Medicine 
(Periodontology), The Hebrew University – 
Hadassah, Jerusalem, Israel
2Universidad Complutense de Madrid 
(ETEP), Madrid, Spain
3Universidad Complutense de Madrid 
(BIOCRAN), Madrid, Spain
Correspondence
Lior Shapira, Department of Periodontology, 
The Hebrew University-Hadassah Medical 
Center, P.O. Box 12272, Jerusalem 91120, 
Israel.
Email: lior.shapira@ekmd.huji.ac.il
Abstract
Aim: To assess the efficacy and adverse effects of resective surgery compared to ac-
cess flap in patients with periodontitis.
Methods: Randomized controlled trials with a follow-up ≥6 months were identified 
in ten databases. Screening, data extraction, and quality assessment were conducted 
by two reviewers. The primary outcome was probing pocket depth, and the main 
secondary outcome was clinical attachment level. Data on adverse events were col-
lected. Meta-analysis was used to synthesize the findings of trials.
Results: A total of 880 publications were identified. Fourteen publications from nine 
clinical trials met the inclusion criteria and were included for analysis. Meta-analysis 
was carried out using all available results. The results indicated superior pocket depth 
reduction following resective surgery compared to access flap after 6–12 months 
of follow-up (weighted mean difference 0.47 mm; confidence interval 0.7–0.24; 
p = .010). After 36–60 months of follow-up, no differences were found between the 
two treatments in pocket depth and attachment level. The prevalence of adverse ef-
fects was not different between the groups. Post-operative recession tended to be 
more severe for the resective approaches.
Conclusion: Resective surgical approach was superior to access flap in reducing 
pocket depth 6–12 months post-surgery, while no differences between the two mo-
dalities were found at 36–60 months of follow-up.
K E Y W O R D S
periodontal pocket, periodontal surgery, periodontitis, pocket reduction, systematic review
www.wileyonlinelibrary.com/journal/jcpe
https://orcid.org/0000-0003-3211-1330
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mailto:
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https://orcid.org/0000-0003-3997-6900
mailto:lior.shapira@ekmd.huji.ac.il
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304  |     POLAK et AL.
and clinical interventions such as supra and subgingival mechani-
cal instrumentation to remove plaque and calculus (Krishna & De 
Stefano, 2016), local and systemic medication (Chambrone et al., 
2016; Jepsen & Jepsen, 2016; Slots, 2012), and surgical interven-
tions (Carnevale, 2007; Cortellini & Tonetti, 2011; Kaldahl, Kalkwarf, 
Patil, Molvar, & Dyer, 1996a; Kirkland & Storer, 1931; Ramfjord & 
Nissle, 1974).
The treatment of periodontitis is initiated by eliminating the in-
fection and controlling its risk factors. This is mostly achieved by a 
non-surgical approach, which aims to diminish inflammation in the 
gingiva and to reduce probing depth. Following treatment, the ideal 
result is shallow periodontal pockets, which enable maintenance of 
periodontal health by a supportive periodontal therapy (SPT) pro-
gramme (Axelsson, Nystrom, & Lindhe, 2004; Graziani, Karapetsa, 
Alonso, & Herrera, 2017).
At times, persistent inflammation and residual deep periodontal 
pockets are present at the end of the anti-infective stage. This out-
come is insufficient for successful supportive therapy, and in such 
cases, surgical intervention is advised.
Patients presenting residual pockets with PPD ≥ 5 mm exhibit a 
higher risk for disease progression and eventually incidence of tooth 
loss (Matuliene et al., 2008,) and teeth with probing depth of 7 mm 
or more are at a significantly higher risk for tooth loss compared with 
shallow PPD (McGuire & Nunn, 1996). As such, residual pockets of 
5 mm or more have been suggested as a clear indication for surgi-
cal intervention (Claffey & Egelberg, 1995; Claffey, Nylund, Kiger, 
Garrett, & Egelberg, 1990; Lindhe, Socransky, Nyman, Haffajee, & 
Westfelt, 1982; Matuliene et al., 2008; Tonetti, Muller-Campanile, 
& Lang, 1998).
The main objective of periodontal surgery is to access difficult to 
reach sites by direct vision and effective debridement, and to enable 
efficient self-performed plaque control and acceptable professional 
supportive therapy (Graziani et al., 2017; Graziani, Karapetsa, Mardas, 
Leow, & Donos, 2018; Heitz-Mayfield & Lang, 2013; Heitz-Mayfield, 
Trombelli, Heitz, Needleman, & Moles, 2002; Isidor & Karring, 1986). 
Ideally, periodontal surgery should result in shallow pockets (<5 mm) 
(Serino, Rosling, Ramberg, Socransky, & Lindhe, 2001). However, oc-
casionally the surgical intervention only reduces deep PPD but not 
completely eliminates it (i.e., residual pockets exceeding 5 mm). While 
those cases are not the desired outcome, they still improve SPT effi-
cacy compared with the pre-surgical state. A variety of surgical tech-
niques exists and their value has been tested over the years, but the 
choice of a surgical approach still relies mainly on the decision-making 
process of the surgeon. The availability of evidence-based information 
for the clinicians as a part of his/her decision-making process should 
optimize the treatment outcome.
Periodontal surgery includes access flap procedures, resective 
procedures, and regenerative procedures. Excluding regeneration 
procedures, the two remaining objectives comprise of two routine 
surgical approaches:
1. Access flap procedures that aim to facilitate visual access with 
minimal reduction in the shape and anatomy of the soft or 
bone tissues (Ammons & Smith, 1976; Cortellini & Tonetti, 
2011; Froum et al., 1982; Heitz-Mayfield et al., 2002; Ramfjord, 
1977; Takei, Han, Carranza, Kenney, & Lekovic, 1985; Wang 
& Greenwell, 2001; Yukna, 1976). The authors included under 
this heading the modified Widman flap (MWF) procedure, since 
its original design was set as access flap surgery, despite the 
fact that the procedure involves minimal soft tissue resection 
to allow healing by primary intention.
2. Pocket reduction/elimination procedures that, in addition to 
debridement with a direct vision, also aim to change the shape 
and outline of the soft and, occasionally hard tissues, in orderto 
achieve controlled PPD reduction (Kaldahl et al., 1996a; Kirkland 
& Storer, 1931; Ochsenbein, 1986; Olsen, Ammons, & Belle, 1985; 
Prichard, 1957; Schluger, 1949; Wang & Greenwell, 2001).
The surgical treatment is expected to predictably improve the 
clinical parameters for long-term maintenance of the affected 
teeth. Several reviews of surgical periodontal procedures have 
been published in the past (Barrington, 1981; 1982; Wirthlin, 
1981; Becker et al., 2001; Nowzari, 2001), and the outcome of the 
surgical approaches has been reported (Becker et al., 2001, 1987; 
Kaldahl, Kalkwarf, Patil, Dyer, & Bates, 1988; Kaldahl, Kalkwarf, 
Patil, Molvar, & Dyer, 1996b; Knowles, Burgett, Morison, Nisle, & 
Ramfjord, 1980; Ramfjord et al., 1987). Nevertheless, a system-
atic comparative analysis of pocket elimination/reduction versus 
access flap procedures and their long-term effectiveness is not 
available.
Clinical Relevance
Scientific rationale for the study: The selection of a specific 
surgical approach should rely on success rate and side ef-
fects as demonstrated in randomized clinical trials. The 
present systematic review analysed the clinical outcomes 
of resective surgery versus access flap procedures in sub-
jects with periodontitis stages II-III (previously termed 
moderate to advanced periodontitis), in order to support 
the development of evidence-based guidelines for peri-
odontal therapy.
Principal findings: The results demonstrated a short-term 
(6–12 months post-treatment) superior pocket depth re-
duction for resective surgery and equivalent outcome for 
the long term (36–60 months post-treatment) compared to 
access flap procedures. The side effects in both modalities 
were similar for all follow-up durations, except for recessions, 
which tended to be more severe for respective surgery.
Practical implications: Since the present review found a 
significant difference between pocket reduction/elimi-
nation versus access flap surgery for the short term only 
(6–12 months), the choice of treatment for each case 
should be depended on patient-specific considerations.
     |  305POLAK et AL.
The aim of the present systematic review was to compare the effi-
cacy of pocket reduction/elimination versus access flap surgical proce-
dures in patients diagnosed with periodontitis. The analysis was limited 
to randomized controlled trials that included an initial step of supra-/
subgingival biofilm control and residual PPD of 5 mm or more.
2  | MATERIAL S AND METHODS
2.1 | Protocol development
The protocol for this systematic review was developed a priori based on 
the corresponding Preferred Reporting Items for Systematic Reviews 
and Meta-analysis (PRISMA) extension30 and registered a priori in 
PROSPERO (ID: CRD42019122805). This review was conducted and re-
ported per the Cochrane Handbook (Higgins et al., 2019) and the PRISMA 
statement (Moher, Liberati, Tetzlaff, & Altman, 2009), respectively.
The following focused PICOS question was proposed: “In adult 
patients with periodontitis after an initial step of supra-/subgingival 
biofilm control and residual PPD of 5 mm or more, what is the effi-
cacy of pocket elimination/reduction surgery in comparison with ac-
cess flap surgery in terms of PPD reduction?” In regard to the details 
of the PICOS question, the population, intervention, comparator, 
outcome, and study design were defined as follows.
2.1.1 | Population
Individuals aged above 18 years with periodontitis, otherwise 
healthy, after the initial step of supra-/subgingival biofilm control 
with residual pockets of 5 mm or more.
2.1.2 | Interventions
Pocket elimination or reduction surgery with or without osteoplasty/
ostectomy (including apically positioned flap and all the modified/per-
tinent techniques that aim to reduce pocket depth by apically position-
ing the soft tissue flap margins and occasionally resect hard tissues).
2.1.3 | Comparator
Access flap surgery, including open flap curettage, open flap de-
bridement, access flap, modified Widman flap (see introduction), and 
all the modified/pertinent techniques that do not include resection 
of soft and hard tissue.
2.1.4 | Outcomes
The primary outcome was PPD reduction measured as mean differ-
ence of pocket depth in millimetres. Secondary outcomes included 
CAL gain as mean difference of clinical attachment level in millime-
tres, bleeding on probing (BOP) reduction; mean difference in the 
percentage of full-mouth bleeding on probing, percentage of pocket 
closure (%); and mean difference in the percentage of pocket clo-
sure, tooth loss. Adverse effects were set as loss of attachment 
and PPD changes in initially shallow pockets and gingival recession. 
Patient-centred/related outcomes included the following: patient 
discomfort/pain, root-surface hypersensitivity, and oral health-re-
lated quality of life.
2.1.5 | Study design
Prospective clinical trials with 6 months or more of follow-up 
duration.
2.2 | Information sources and search strategy
A comprehensive literature search was performed in duplicate 
(Table S1) from inception of each database up to January 24 2019 in 
seven electronic databases (MEDLINE, Scopus, Cochrane CENTRAL, 
Cochrane DARE, Web of Science, SciELO, LILACS, BBO, and DECS) 
without any limitations to publication year, language, type, or sta-
tus (supplementary Table S1). In addition, several trial registers (Clini 
calTr ials.gov, UK clinical trials Gateway) were manually searched for 
any missed studies.
The following search strategy was developed: (pocket elimina-
tion surgery OR pocket reduction surgery OR periodontal flap sur-
gery OR periodontal pocket surgery OR apically displaced flap OR 
apically repositioned flap OR apically positioned flap OR Neumann 
flap OR ostectomy OR osteoplasty OR osseous surgery OR gingi-
vectomy) AND (access flap OR modified Widman OR open flap 
curettage OR open flap debridement OR Kirkland flap OR papilla 
preservation flap OR un-displaced flap) AND (longitudinal study 
OR randomised controlled study OR comparative study OR clinical 
trial) NOT (systematic review*[tiab] OR systematic literature[tiab] 
OR meta-analysis[tiab] OR meta-analyses[tiab] OR in vitro[tiab] OR 
animal*[tiab]).
Selected databases considered as grey literature databases 
(Mahood, Eerd, & Irvin, 2014) did not allow for the recording of the 
reference lists in separate files and were therefore searched manu-
ally. Reference lists of retrieved papers and of previously published 
systematic reviews were also hand-searched. The search queries on 
the previous were modified in order to allow the yielding of the max-
imum number of hits.
2.3 | Study eligibility criteria
This systematic review included only randomized controlled tri-
als (RCTs, parallel, and split-mouth) as they are considered the most 
robust study for medical intervention assessment (Altman & Schulz, 
http://ClinicalTrials.gov
http://ClinicalTrials.gov
306  |     POLAK et AL.
2001). Non-randomized prospective controlled studies were planned 
to be included in order to provide as much as possible of the available 
published evidence, but none were identified.
2.3.1 | Inclusion criteria
Prospective controlled clinical trials with more than 10 human sub-
jects per group, patients >18 years old with periodontitis, all patients 
received full-mouth clinical examination (all teeth examined, with ≥4 
sites per tooth), treated teeth had PPD of ≥5 mm, control groups un-
derwent subgingival debridement with access flap or sister technique, 
and reports included PPD and CAL, 6 months or more of follow-up.
2.3.2 | Exclusion criteria
Use of biomaterials/additional procedures for the same surgery in-
cluding regenerative procedures, endodontic-periodontal lesions, 
periodontal treatment aiming to treat specifically furcation involve-
ments (since this issue is specifically addressed in another systematic 
review in the current workshop), and studies published as editorials, 
letters, comments, case series,and case report.
2.4 | Record screening, selection, and data 
extraction process
2.4.1 | Screening and selection
Two reviewers (PD & WA) performed the search and selected eligi-
ble studies by reviewing the list of titles and abstracts independently. 
Studies were selected when appearing to meet the selection cri-
teria, or when there were insufficient data to make a clear decision. 
Discrepancies between these reviewers pertaining to the selection and 
inclusion of any specific paper were solved by a third reviewer (ANG). 
In the second stage, the full text of the selected articles was assessed 
by two reviewers (SL & WA). All articles that did not fulfil all the selec-
tion criteria were eliminated, and reasons for exclusion were recorded. 
All reports excluded at this stage were formally recorded, as well as the 
reason/s for their exclusion. Due to the limited number of identified eli-
gible trials, the authors included two trials in which periodontal surgery 
was also performed prior to initial scaling and root planing (Kaldahl et 
al., 1988, 1996b; Westfelt et al., 1985). Inter-observer agreement value 
for the screening of complete articles was assessed via kappa score. 
Disagreements were resolved by consulting a third reviewer (ANG), and 
the kappa score was calculated. Special attention was paid to duplicate 
publications to avoid an effect on the agreement assessment.
2.5 | Data extraction
Based on the Cochrane recommendations, a standardized, pre-
piloted data extraction form was designed and used. Data were 
extracted from eligible studies and recorded by two reviewers (PD 
& ANG). Data extraction included study design (year of publication, 
study type, randomization process, setting, funding), patient charac-
teristics (number, sex, age, disease severity, smoking), surgical char-
acteristics (surgery type, brief description of surgery), maintenance 
protocol, and clinical measurements of the outcomes of interest and 
adverse effects. A third reviewer solved disagreements and cross-
checked the accuracy and validity of all the data obtained from the 
studies (MC). Authors of studies or published protocols were con-
tacted for further information when data were incomplete or miss-
ing. When the results of a study were published more than once or if 
the results were presented in different publications, the most com-
plete data set was included only once.
2.6 | Risk of bias of individual studies and 
reporting quality
The quality assessment of the included studies was undertaken by two 
reviewers (MC & ANG) following the recommendations by Cochrane 
for assessing the risk of bias (RoB) (Higgins et al., 2011) and evaluating 
six criteria. RevMan software (Review Manager, version 5.2., Cochrane 
Collaboration) was used to obtain the RoB figures. Studies were defined 
as low RoB if these six criteria were clearly met in the study: random 
sequence allocation (selection bias), allocation concealment (selection 
bias), blinding of participants and personnel (performance bias), bias 
of outcome assessment (detection bias), incomplete outcome data (at-
trition bias), selective reporting (reporting bias), and other bias. When 
missing one of these criteria, the study was classified as a “moderate 
potential risk of bias.” Missing two or more of these criteria resulted in a 
high potential risk of bias (Ten Heggeler, Slot, & Weijden, 2011). Other 
aspects regarding the quality of the studies were recorded in the re-
porting quality assessment table based on some items extracted from 
the CONSORT guidelines (Schulz, Altman, & Moher, 2010).
For interventional, non-randomized controlled trials, the 
Cochrane tool—ROBINS-I— was planned to be used (Sterne et al., 
2016).
2.7 | Data analyses
A quantitative synthesis of aggregate data was planned to be per-
formed. To compare the selected studies, data on the primary (PPD 
reduction) and secondary outcomes (CAL gain) were pooled and 
analysed using weighted mean differences (WMDs) and 95% coef-
ficient interval (CI).
When the differences between (∆) baseline-end were not re-
ported, they were calculated using baseline and final values. The 
variance of ∆Var was estimated with the formula: SVar2 = SVar12 
+ SVar22 − (2*r*SVar1*SVar2), where SVar2 is the variance of the 
difference, SVar12 is the variance of the mean baseline value, and 
Svar22 is the variance of the mean end value. A correlation r of 0.5 
was assumed. If treatment effects (mean or standard deviation) were 
not reported in publications, authors were contacted.
     |  307POLAK et AL.
The statistical heterogeneity among studies was assessed using 
the Q test according to DerSimonian and Laird (DerSimonian & 
Laird, 1986). As a complement to the Q test, the I2 index (Higgins, 
Thompson, Deeks, & Altman, 2003) was calculated in order to know 
the percentage of variation in the global estimate that was attribut-
able to heterogeneity (I2 = 25%: low; I2 = 50%: moderate; I2 = 75%: 
high heterogeneity). In case of heterogeneity, in addition to the sum-
mary estimate (WMD) and CI, prediction intervals will be reported to 
allow more informative inferences and illustrate which range of true 
effects can be expected in future settings, presenting the heteroge-
neity in the same metric as the original effect size measure (IntHout, 
Ioannidis, Rovers, & Goeman, 2016).
In addition, sources of heterogeneity were planned to be ana-
lysed through pre-specified mixed-effects subgroup analyses and 
random-effects meta-regression using the following factors: (a) 
% of smokers (or different subgroups if provided, e.g. smokers vs. 
non-smokers) and (b) subsets of increasing periodontitis severity 
(4–6 mm PPD & >7 mm PPD). The study-specific estimates were 
pooled using both the fixed effect model (Mantel–Haenszel–Peto 
test) and the random effect model (DerSimonian–Laird test). If sig-
nificant heterogeneity was found, the random effect model results 
were presented.
Subgroup analysis (using the factors mentioned above), meta-re-
gression, or network meta-analysis was considered in case the avail-
able data allowed for these types of analysis.
Forest plots were created to illustrate the effects in the me-
ta-analysis of the global estimation and the different sub-analysis. 
STATA® 14 (StataCorp LP, Lakeway Drive) intercooled software 
was used to perform all analyses. Statistical significance was set at 
p ≤ .05.
A summary of the key findings from the systematic review was 
presented using the GRADE approach in the form of a Summary of 
Findings (SoF) for grading the quality of evidence and the strength 
of our recommendations (Guyatt et al., 2011).
2.8 | Methods for addressing reporting biases
Publication bias was addressed in different ways: (a) in case of a 
sufficient number of included studies (at least 10 studies; with 
fewer studies, the power of the tests is too low to distinguish 
chance from real asymmetry), funnel plots were planned to be 
used, although an asymmetrical funnel plot should not be equated 
with publication bias, (b) Egger's test was planned to be used to 
F I G U R E 1   Flow chart
308  |     POLAK et AL.
assess publication bias, and (c) results of tests for funnel plot asym-
metry were planned to be interpreted in the light of visual inspec-
tion of the funnel plot. The contribution made to the totality of 
the evidence by studies with statistically non-significant results 
compared to that from studies with statistically significant results 
will be taken into account.
3  | RESULTS
3.1 | Study selection
Figure 1 depicts the study flow chart. The electronic search yielded 
878 titles. The manual search added 2 additional studies, with a total 
of 880 studies. After the screening of titles and abstracts, 851 stud-
ies were discarded (agreement = 97.44%; kappa = 0.705; p < .001) 
resulting in 29 studies. Following the review of the full-text articles, 
15 studies were excluded and 14 were included in the qualitative 
synthesis (agreement = 93.10%; kappa= 0.877; p < .001), represent-
ing 9 different studies. Excluded studies and reasons for exclusion 
are shown in Table S2. Five publications, corresponding to three tri-
als, were considered for the quantitative synthesis.
3.2 | Study characteristics
The methodological characteristics of the selected studies are pre-
sented in Table 1. Some studies are presented in more than one 
publication, and these papers were united into one unit of analysis 
in the current report (Table 1). Most studies were based on a split-
mouth design, and only three studies (Kyriazis et al., 2012; Nyman, 
Lindhe, & Rosling, 1977; Rosling, Nyman, Lindhe, & Jern, 1976) 
were based on a parallel-group design. Furthermore, the major-
ity of the studies were conducted and published in the 1970s and 
1980s, and only two articles were published after the year 2000 
(Becker et al., 2001; Kyriazis et al., 2012), and of those only one 
study was performed after the year 2000 (Kyriazis et al., 2012). 
Table 2 summarizes the outcome variables of interest, surgical 
techniques, maintenance protocol, and adverse effects in the in-
cluded trials.
3.3 | Risk of bias in individual studies
Table S3 shows the risk of bias assessment as recommended by 
Cochrane. None of the 14 included studies could be qualified as 
having a low risk of bias since the information reported did not 
provide enough data to evaluate whether a criterion was met and 
therefore rated as unclear in many cases. The number of studies 
that had low risk of bias for specific criteria varied according to 
the assessed item: random sequence generation (n = 5), alloca-
tion concealment (n = 1), blinding of participants (n = 7), blinding 
of outcome assessment (n = 5), incomplete outcome data (n = 5), TA
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     |  309POLAK et AL.
TA
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, w
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ks
.
310  |     POLAK et AL.
and selective reporting (n = 11). Regarding the independence of 
the study, in terms of funding, half of the studies (n = 8) did not 
report this aspect and the rest were either public or self-funded. 
All authors were independent researchers, which was considered 
as a low risk of bias. Figures S1 and S2 summarize this information 
graphically.
3.4 | Quality of design and reporting in 
individual studies
Table S4 shows the items related to registration according to the 
information provided in the 14 included studies: ethical commit-
tee approval (n = 4), informed consent (n = 8), reporting adherence 
to the CONSORT guidelines (n = 1), and registration of the RCT 
(n = 1). In the same table, aspects related to the statistical analyses 
and outcome assessment are summarized, showing the number of 
manuscripts reporting sample size and/or power analysis calculation 
(n = 1), the primary statistical test (n = 14), an intent-to-treat analysis 
(n = 0), calibration (n = 10), the number of examiners (n = 9), and their 
skills/experience (n = 9).
3.5 | Synthesis of the results
Of the included publications, five presented the results in graphi-
cal illustrations and not as values (Isidor, Karring, & Attström,1984; 
Kaldahl et al., 1996a; Nyman et al., 1977; Rosling, Nyman, & Lindhe, 
1976), excluding them from the quantitative synthesis. The results 
of those studies and all other included publications are addressed in 
a narrative analysis that presents the summation of all publications.
The follow-up duration of the included publications was up to 
seven years. PPD reduction following pocket reduction surgery 
showed diversity between groups, but overall showed superior re-
duction compared to access flap during the first year post-surgery. 
However, in the long term (>3 years), no statistical differences in 
PPD reduction were found between the groups.
Studies based on parallel study design (Kyriazis et al., 2012; 
Nyman et al., 1977; Rosling et al., 1976) show a similar pattern of re-
sults as studies that used a split-mouth design. Kyriazis et al. found 
improved pocket reduction and CAL gain using apically positioned flap 
compared to MWF, with statistically significant differences between 
groups (Kyriazis et al., 2012). However, Rosling et al. (1976). demon-
strated superior CAL gain for MWF compared to apically positioned 
F I G U R E 2   Forest plots showing comparisons of PPD (Probing Pocket Depth) changes (in mm) between groups. Subgroup analysis 
according severity of initial PPD: 1 = pockets 4–6 mm and 5–6 mm; 2 = pockets ≥7 mm. (a) 6-month follow-up results; (b) 12-month follow-
up results; (c) 36-month follow-up results, and (d) 60-month follow-up results. Data presented in values are also available at Table S5. WMD, 
weighted mean difference; 95% CI, 95% confidence interval [Colour figure can be viewed at wileyonlinelibrary.com]
www.wileyonlinelibrary.com
     |  311POLAK et AL.
flap (Rosling et al., 1976). Nyman et al. did not show any difference be-
tween groups regarding changes in PPD and CAL (Nyman et al., 1977).
In accordance with the outcome variables analysed in the current 
review, adverse effect was set as loss of attachment in initially shal-
low pockets (as primary outcome) and PPD changes (as secondary 
outcome). Analysis according to initial pockets (Becker et al., 2001, 
1987; Hill et al., 1981; Kaldahl et al., 1988; Ramfjord et al., 1987) 
showed primary CAL loss in initial shallow pockets in both treatment 
modalities. Data regarding patient discomfort/pain, root-surface hy-
persensitivity, and oral health-related quality of life were not avail-
able in most of the included studies and thus were not included in 
the adverse effect analysis. For a similar reason, BOP, percentage of 
pocket closure, and tooth loss as secondary outcome variables were 
not analysed.
Post-operative recessions may also be considered as an adverse 
effect. Most studies did not report post-surgical recession, and 
only four publications from two clinical trials (Becker et al., 2001, 
1987; Kaldahl et al., 1988, 1996a, 1996b) presented recession val-
ues. In shallow pockets (1–3 mm), both trials showed that recession 
severity was higher following resective surgery than after access 
flap approach. Becker et al. showed post-operative recession mean 
of 0.95 ± 0.58 mm for resective surgery and 0.66 ± 0.4 mm for 
access flap at one year, and 0.85 ± 0.52 mm and 0.57 ± 0.48 mm, 
respectively, at five years. Similarly, Kaldahl et al., 1988, found 
0.89 ± 0.1 mm recession post-resective surgery and 0.38 ± 0.06 mm 
post-access flap after 2 years of follow-up.
Moderately deep to deep initial pockets exhibited more re-
cession than shallow initial pockets. Both studies showed higher 
F I G U R E 3   Meta-regressions showing 
comparisons of PPD (probing pocket 
depth) changes (in mm) between groups 
with follow-up (in months) as a covariate. 
(a) Intermediate pockets (4–6 mm and 
5–6 mm); (b) Deep pockets (≥7 mm). Data 
presented in values are also available 
at Table S6. WMD, weighted mean 
difference [Colour figure can be viewed at 
wileyonlinelibrary.com]
www.wileyonlinelibrary.com
312  |     POLAK et AL.
recession values following resective surgery compared to access flap 
at 1 year post-surgery (moderately deep pockets: 1.25 ± 0.59 mm 
vs. 1.05 ± 0.59 mm for Becker et al., and 1.87 ± 0.09 mm vs. 
0.65 ± 0.07 mm for Kaldahl et al.; deep pockets: 2.42 ± 0.91mm 
vs. 1.83 ± 0.84 mm for Becker et al., and 2.49 ± 0.12 mm vs. 
1.02 ± 0.11 mm for Kaldahl et al.). However, at the five years of fol-
low-up, Becker et al. did not find a difference in recession values be-
tween the two modalities (moderately deep pockets: 1.03 ± 0.46 mm 
vs. 0.94 ± 0.74 mm; deep pockets: 1.7 ± 1.23mm vs. 2.18 ± 1.86 mm), 
while Kaldahl et al. showed higher recession values following resec-
tive surgery compared to access flap (moderately deep pockets: 
1.2 ± 0.12 mm vs. 0.48 ± 0.07 mm; deep pockets: 1.54 ± 0.14 mm 
vs. 0.71 ± 0.11 mm).
3.6 | Quantitative analysis
Probing pocket depth analysis according to follow-up duration and 
initial pocket depth showed, at 6 and 12 months, better results for 
pocket reduction surgery compared to access flap procedures, with 
a mean difference of 0.59 mm (95% CI: −1.12, −0.06; 95% prediction 
interval ranged from −3.05 to 1.86) and 0.47 mm (95% CI: −0.70, 
−0.24; 95% prediction interval ranged from −1.17 to 0.23) for 6 and 
12 months, respectively (Figure 2; Table S5). In the 12 months of fol-
low-up interval, moderately deep pockets (4–6 mm) showed modest 
differences between the two tested modalities (mean difference of 
0.34 mm; 95% CI: −0.48, −0.19; 95% prediction interval ranged from 
−1.55 to 0.88), while deep pockets (>7 mm; 95% CI: −1.17, −0.35) 
showed a greater difference between the groups (0.76 mm, 95% pre-
diction interval ranged from −4.68 to 3.16). At 36 and 60 months 
of follow-up, the differences between the groups were markedly 
reduced with mean PPD reduction difference of 0.05 mm (95%CI: 
−0.39, 0.28; 95% prediction interval ranged from −1.27 to 1.17) for 
36 months and 0.1 mm (95%CI: −0.31, 0.12; 95% prediction interval 
ranged from −0.57 to 0.38) for 60 months. At those follow-up inter-
vals, no differences were found between moderately deep and deep 
initial pockets (Figure 2). Meta-regression models exhibit a reduction 
in the differences in PPD between the two treatment modalities, 
with a similar pattern for moderately deep and deep initial pockets 
(Figure 3; Table S6).
Clinical attachment level analysis shows similar results as the PPD, 
with greater CAL gain for pocket reduction procedure at 6 months 
(mean differences of 0.28 mm; 95% CI: −0.12, 0.68; 95% prediction 
interval ranged from −1.50 to 2.05), and limited differences at all the 
F I G U R E 4   Forest plots showing comparisons of CAL (clinical attachment level) changes (in mm) between groups. Subgroup analysis 
according severity of initial PPD (probing pocket depth): 1 = pockets 4–6 mm and 5–6 mm; 2 = pockets ≥7 mm. (a) 6-month follow-up results; 
(b) 12-month follow-up results; (c) 36-month follow-up results; and d, 60-month follow-up results. Data presented in values are also available 
at Table S5. WMD, weighted mean difference; 95% CI, 95% confidence interval [Colour figure can be viewed at wileyonlinelibrary.com]
www.wileyonlinelibrary.com
     |  313POLAK et AL.
other tested follow-up intervals, ranging between 0.13 mm (95% CI: 
−0.11, 0.38; 95% prediction interval ranged from −0.54 to 0.81) and 
0.17 mm (95% CI: −0.14, 0.48; 95% prediction interval ranged from 
−0.85 to 1.19) (Figure 4; Table S5). Furthermore, initially deep pock-
ets showed more CAL gain than initially moderately deep pockets at 
6 months of follow-up (Figure 3). Meta-regression analysis of initial 
moderately deep and deep pockets shows an initial superior CAL 
gain for pocket reduction procedures compared to access flap, with 
no difference between the procedures in the long-term follow-up 
(Figure 5; Table S6).
Clinical attachment level loss and increased PPD for initially shal-
low pockets were considered as adverse effects. The results showed 
an increase in CAL of 0.25 mm (95%CI: 0.16, 0.35;95% prediction in-
terval ranged from −0.08 to 0.59) for pocket reduction surgery com-
pared to access flap (Figure 6; Table S7). This difference tended to 
reduce over time, as can be seen from the meta-regression analysis 
(for follow-up= −0.0038; 95% CI: −0.01 to 1, Figure 7). PPD changes 
showed a modest difference between the 2 surgical modalities of 
0.03 mm (95%CI: −0.04, 0.1; 95% prediction interval ranged from 
−0.24 to 0.30), with stability of the results at all tested intervals. 
Meta-regression results were similar to PPD changes (coefficient 
for follow-up= −0.0035; 95% CI: −0.01 to 1, Figure S5). There were 
no remarkable differences in PPD between the 2 treatment modal-
ities in shallow pockets, and their effect varied between 0.01 and 
0.33 mm (Table S7).
A summary of the key findings (SoF) from this systematic review 
is presented in Table S8 using the GRADE method. The following out-
come variables were included and assessed in the SoF table: PPD re-
duction and CAL changes for moderately deep and deep pockets at 
12 months of follow-up, and CAL changes at 60 months of follow-up.
F I G U R E 5   Meta-regressions showing 
comparisons of CAL (clinical attachment 
level) changes (in mm) between groups 
with follow-up (in months) as covariate. 
(a) Intermediate pocket (4-6 mm) analysis; 
(b) deep pocket (≥7 mm) analysis. Data 
presented in values are also available 
at Table S6. WMD, weighted mean 
difference [Colour figure can be viewed at 
wileyonlinelibrary.com]
www.wileyonlinelibrary.com
314  |     POLAK et AL.
4  | DISCUSSION
While individual studies describe and indicate the advantages of sur-
gical procedures and provide valuable clinical information, system-
atic analysis of controlled trials is required as part of the decisions 
making process in clinical situations. The current systematic review 
illustrates the limited amount and heterogeneous available studies 
focusing on access flap and resective surgery.
The results of the current review demonstrate a short-term su-
perior outcome in PPD reduction for resective surgery compared 
F I G U R E 6   Forest plots for adverse 
effects. (a) CAL (clinical attachment level) 
changes (in mm) and (b) PPD (probing 
pocket depth) changes (in mm). Subgroup 
analysis according to follow-up (in 
months): 6, 12, 24, 36, 48, and 60 months. 
Data presented in values are also available 
at Table S7. ARF, apically repositioned 
flap; WMD, weighted mean difference; 
95% CI: 95% confidence interval [Colour 
figure can be viewed at wileyonlinelibrary.
com]
www.wileyonlinelibrary.com
www.wileyonlinelibrary.com
     |  315POLAK et AL.
to access flap procedures, alongside a "cost" of attachment level 
loss. This was more evident for initially deep pockets (>7 mm) than 
moderately deep pockets (4–6 mm). However, in the long-term fol-
low-up, the superiority of resective surgery diminished, and the 
two approaches demonstrate an equivalent outcome. Similarly, 
CAL changes show comparable long-term outcomes for resective 
and access flap procedures. Taken together, resective surgery ap-
proach provides transient superior PPD reduction and long-term 
equivalent effectiveness compared with access flap approach. The 
side effect of both approaches was PPD and CAL deterioration in 
sites with initial shallow pockets, but the differences between the 
two approaches were minimal (0.25 mm of ΔPPD and 0.03 mm of 
ΔCAL), with minimal clinical significance. It should be stated that the 
meta-analyses in the current review are based on 2–3 studies, and 
not all of the studies provided data for the long-term analyses (36 
and 60 months).
Unfortunately, there is the lack of publications in the last two 
decades related to access flap or pockets reduction surgical proce-
dures, with scarce description of surgical techniques or reviews of 
techniques (Carnevale, 2007; Cortellini & Tonetti, 2011; Graziani 
et al., 2012; Nowzari, 2001) and only one new RCT (Kyriazis et 
al., 2012). Considering the limited outcome of non-surgical ther-
apy in deep pockets (Heitz-Mayfield & Lang, 2013) and the lim-
ited anatomical conditions which allow predictable regenerative 
procedures (Avila-Ortiz, Buitrago, & Reddy, 2015; Kao, Nares, & 
Reynolds, 2015), non-regenerative surgical approaches are an 
essential and common part of periodontal therapy. The lack of 
evidence derived from the lack of research with contemporary 
methodology, absence of studies using newly acceptable end-
points (such as “closed pockets”), and the lack of evidence from 
studies implementing modern surgical approaches (i.e., micro-
surgery, use of magnification systems, etc.) preclude definitive 
F I G U R E 7   Meta-regression for 
adverse effects. (a) CAL (clinical 
attachment level) changes (in mm) 
between groups in shallow pockets with 
follow-up (in months) as a covariate. (b) 
PPD (probing pocket depth) changes 
(in mm) between groups in shallow 
pockets with follow-up as (in months) 
covariate [Colour figure can be viewed at 
wileyonlinelibrary.com]
www.wileyonlinelibrary.com
316  |     POLAK et AL.
conclusions. On the other hand, the strength of the included RCTs 
lies in the long-term follow-up.
Most of the included studies used a split-mouth design, which 
has the weakness of carry-across effect (Lesaffre, Philstrom, 
Needleman, & Worthington, 2009). This is based on the microbial 
aetiology of periodontitis that postulates potential changes of the 
oral microbiota when one niche of a quadrant is treated, it may affect 
the other quadrants in the same subject. However, this design pro-
vides the advantage of subject variable response to therapy.
Of interest is the possible impact of SPT protocols of the tri-
als on the results. Some of the included studies included very fre-
quent SPT at two-week intervals (Isidor & Karring, 1986; Nyman et 
al., 1977; Rosling et al., 1976; Westfelt et al., 1985), while in other 
studies SPT was performed every 3 months (Becker et al., 2001, 
1987; Hill et al., 1981; Kaldahl et al., 1988, 1996a, 1996b; Ramfjord 
et al., 1987). Since the results of all studies are relatively uniform, it 
seems that SPT every 3 months may be sufficient. Moreover, since 
the majority of studies were carried out decades ago, current RCT 
guidelines did not apply (such as non-split-mouth design). When con-
sidering only the parallel design studies (three studies) (Kyriazis et 
al., 2012; Nyman et al., 1977; Rosling et al., 1976), their results are 
conflicting and prevent a concrete and uniform clinical conclusions. 
Nevertheless, the fact is that SPT has a substantial impact on the 
recurrence of periodontitis (Costa et al., 2015). Therefore, it is rea-
sonable to conclude that a meticulous SPT programme is mandatory 
to maximize any surgical outcome.
Based on the risk of bias of individual studies and on the risk of 
bias assessment using the RoB tool, most factors that would introduce 
bias were undetectable or absent. Nonetheless, loses to follow-up 
and inadequate blinding were frequently encountered in the included 
RCTs. The overall quality of the individual studies was considered poor 
although this needs to be evaluated in the specific historical context. 
Publication bias tests were not performed due to the limited number 
of studies that could be used for this purpose.
In addition, the quality of evidence across studies assessing se-
lected outcomes was deemed “LOW” in relation to all outcomes due 
to the possibility of serious risk of bias and imprecision of the clin-
ical measurements. This can be explained by the fact that all three 
studies that dropped data considered in the Summary of Findings 
table (Table S8) were rated with 2 or more domains of unclear risk 
of bias using the RoB tool. Also, the inherent imprecision of clinical 
measurement using periodontal probes has a considerable effect 
on assessing effects lower than 2 mm. The former may reduce the 
confidence of our conclusions because the observed effects can be 
substantiallydifferent from the true effects.
The present systematic review focused on PPD reduction and 
CAL changes despite the fact that these clinical parameters are weak 
predictors of long-term disease progression or as risk markers for 
tooth loss. There is a great need to single out more reliable indices 
for risk assessment, and include them in future RCTs that compare 
periodontal surgical approaches. In addition, the difference between 
the surgical approaches was small, and it would be beneficial to carry 
out an additional assessment of the effect size (%) for the overall 
changes in different PPDs. However, such analysis was not possible 
due to the presentation of the results in the RCTs by pocket depth 
groups only.
In conclusion, when the aim of the periodontal treatment is to 
reduce the depth of the residual periodontal pockets:
1. Pocket reduction/elimination techniques were found to be su-
perior to access flap approaches 6–12 months post-surgery, 
particularly in sites with initial PPD of >6 mm.
2. Longer-term follow-up (36–60 months) was not able to find sig-
nificant differences between the two surgical approaches.
Clinically, since the present review found a significant difference 
between pocket reduction/elimination versus access flap surgery for 
the short term (6–12 months) only, the authors feel that the choice 
of treatment for each case may rely on other factors, such as the sur-
geon's experience as well as individual patient-related preferences, 
aesthetic considerations, and post-surgical restorative aspects.
CONFLIC T OF INTERE S T
Dr. Shapira reports grants from MIS Implants; personal fees from 
MIS Implants Technologies, Dexcel Pharma, and BoneSci; and other 
from Datum Dental, outside the submitted work. Dr. Goldstein re-
ports personal fees from MIS Implants Technologies outside and 
with no possible conflict to the submitted work. Dr. Polak reports 
personal fees from Dexcel Pharma, outside the submitted work. Dr. 
Antonoglou, Dr. Martin, and Dr. Wilensky have nothing to disclose.
ORCID
David Polak https://orcid.org/0000-0003-3211-1330 
Georgios N. Antonoglou https://orcid.
org/0000-0002-8254-5471 
Lior Shapira https://orcid.org/0000-0001-9145-5155 
Conchita Martin https://orcid.org/0000-0003-3997-6900 
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SUPPORTING INFORMATION
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Supporting Information section. 
How to cite this article: Polak D, Wilensky A, Antonoglou 
GN, Shapira L, Goldstein M, Martin C. The efficacy of pocket 
elimination/reduction compared to access flap surgery: A 
systematic review and meta-analysis. J Clin Periodontol. 
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